4
www.tilleygroup.co.nz PERFORATED METAL TECHNICAL DATA
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PERFORATED METALTECHNICAL DATA
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MARGINS AND PERFORATED AREASA major advantage of perforated metal plates is that they can be produced with unperforated or plain margins on 4 sides, or with perforated areas of various shapes alternating with unperforated areas. This is particularly important if the metal
The designer can exploit the capabilities of modern punching presses to obtain a perforated plate that can be directly
additional components.
of a metal sheet with irregular full areas alternating with perforated areas. The full areas and margins are always measured from the outside edge of the holes.
Technical drawings show perforated metal plates from the punch-entry side. It is in any case advisable to specify the burr side for asymmetrical perforated plates. This becomes mandatory if the plates are to undergo additional operations such as bending.
We should note that wide margins or large unperforated
mechanical stress of perforation causes bulging and buckling that, in extreme cases, cannot be corrected even with highly sophisticated leveling rolls.
Large unperforated areas can also produce dimensional
operation therefore becomes necessary when tolerances are tight. Because of the substantial irregularities that result from
from the nominal values.
PERFORATED METALTECHNICAL DATA
Copyright. All intellectual property is owned by Tilley Group Ltd, dimensions and specifications are subject to change.
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HOLE SHAPE AND ARRANGEMENTA.E Tilley uses the following guidelines when describing hole shape and arrangement.
Shape of holes Arrangement of holes Examples
T10
20
15R
R = Round holes T = Triangular pitch
U
U U = Rectangular pitch R 10 U 15 x 20C
C = Square holes
Z
Z
5
5
20
15Z = Staggered pitch
HH = Hexagonal holes
M
C 5 Z 15 x 20M = Diagonal pitch
LR LR = Slot holes
LC LC = Rectangular holes
CDCD = Square, diagonal
Perforated sheet with marginsM4
M1M2
M3
6
18 18 4 12
5
2
5
7 8
13
19
1520
11
10
12 16 14
11
20
191
12
1112
18
17
9
4
3
MARGINS LEGEND
TOOLSETTINGS
DESCRIPTION OF A PERFORATED SHEET
Fig. A
1.
Fig. B
2.
Fig. C
3.
1 Length
2 Width
3 Sheet thickness
4 Margins (long sides)
5 Margins (short sides)
6 Hole size
7 Triangular pitch, longitudinal
8 Triangular pitch, transverse
9 Rectangular pitch
10 Diagonal pitch
11 Staggered pitch parallel to width
12 Staggered pitch parallel to length
13 End staggered pitch, parallel to width
14 End staggered pitch, parallel to length
15 Rectangular pitch parallel to width
16 Rectangular pitch parallel to length
17 Measure of pitch
18 Row of holes
19 Slot hole length
20 Slot hole width
PERFORATED METALTECHNICAL DATA
Copyright. All intellectual property is owned by Tilley Group Ltd, dimensions and specifications are subject to change.
WELLINGTON HEAD OFFICE1-7 Jean Batten St, Rongotai, Wellington 6022PO Box 14122, Kilbirnie, Wellington 6241, New ZealandT +64 4 387 7009 E [email protected] AUCKLAND SALES OFFICE36 Aranui Rd, Mt Wellington, Auckland 1060New ZealandT +64 9 527 7385 E [email protected] CHRISTCHURCH SALES OFFICELevel 1/306 Port Hills Rd, Hillsborough, Christchurch 8022New ZealandT +64 3 331 6565 E [email protected]
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PERFORATION FORMULAS
Arrangement of holes Number of holes per sq. mOpen area %Description
TT
TR
R – TR2 x 90.69
T21,154,700
T2
R – UU1
R U2
R2 x 78.5U1 x U2
1,000,000U1 x U2
U1
U2C
C – UC2 x 100U1 x U2
1,000,000U1 x U2
C Z2
Z1C - Z1, Z2
C2 x 1000.5 x (Z1 x Z2)
1,000,0000.5 x (Z1 x Z2)
L Z2
Z1
RLR - Z1, Z2
(L x R - 0.215R2) x 1000.5 x (Z1 x Z2)
1,000,0000.5 x (Z1 x Z2)
Z1
CLZ 2
LC - Z1, Z2L x C x 100
0.5 x (Z1 x Z2)1,000,000
0.5 x (Z1 x Z2)
PERFORATED METALTECHNICAL DATA
Copyright. All intellectual property is owned by Tilley Group Ltd, dimensions and specifications are subject to change.
